1. Field of the Invention
The present invention relates to an image display apparatus displaying an image in accordance with inputted image data, and to a method for adjusting display luminance of the image in accordance with surrounding illuminance of the apparatus.
2. Description of the Related Art
It is known that the human eye has a high resolution performance for brightness in low luminance light (dark light), and a low resolution performance for high luminance light (bright light). Therefore, the human can well perceive tone variation of an image in a dark room (under an environment of low surrounding illuminance), but cannot well perceive tone variation of an image in a bright room (under an environment of high surrounding illuminance). Further, it is pointed out that this effect on perception of tone variation caused by the surrounding illuminance is significant in the perception of the low-tone portion in an image. In the Japanese Unexamined Patent Application Publication No. 2004-272156, an image display apparatus, in which surrounding illuminance of the apparatus is measured, and in the case of low illuminance, display luminance of the low-tone portion in the image display apparatus is reduced, and the image is displayed in small tone variations (small luminance variation), and in the case of high illuminance, display luminance of the low-tone portion in the image display apparatus is increased, and the image is displayed in large tone variations (large luminance variation), is disclosed.